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This list seams to want to be a place to be petty - it's not for me - bye

Doug

--- In Electronics_101@y..., Jim Purcell <jpurcell@w...> wrote:

Steve,

After working in the RF realm for many years, I had begun to wonder about
this same question...

Since you didn't quote or paraphrase I have no idea what question you've been
wondering about.

Jim

uhhh.... yeah... well, the uhh, "subject" header does sorta state the question pretty plainly.

but I do get your point, I did sorta forget to address my response to the person asking the question and to the question itself.

I'll make it a point in future posts to be more concise. please don't tell Miss Manners about my egregious omission?

Steve

Hello,

I'm a new addition to this group. 1215 members? wow! I had to see what all the commotion was about.

A question to get rolling: How does a choke work? How are they made?

thanks.

Steve.

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In the case of the question about where the charge in a capacitor
lies - yes, we should ask the physics group.
- mark

--- In Electronics_101@y..., "d nixon" <dnixon9@h...> wrote:

Yes, microcontrollers are electronic devices, but the discussion of

them has

generated so much traffic that they have their own group.

Should we discuss electronics on the Physics group?

-Mike

From: Mounir Shita <mshita@c...>
Reply-To: Electronics_101@y...
To: "'Electronics_101@y...'" <Electronics_101@y...>
Subject: RE: [Electronics_101] Re: PIC resources
Date: Thu, 1 Nov 2001 17:26:16 -0500

I would disagree with everyone who thinks PIC discussions doesn't

belong to

this group either. I think we're beyond the times where you could

do

everything with discrete components. These days microcontrollers

belong as

much to Basic Electronics as a transistor and a diode.

Mounir

-----Original Message-----
From: d nixon [mailto:dnixon9@h...]
Sent: Thursday, November 01, 2001 2:23 PM
To: Electronics_101@y...
Subject: Re: [Electronics_101] Re: PIC resources


You'd get a better answer on the PIC group.

From: "Teodoro M. Villamarzo" <tedmv@m...>
Reply-To: Electronics_101@y...
To: Electronics_101@y...
Subject: Re: [Electronics_101] Re: PIC resources
Date: Thu, 01 Nov 2001 12:28:19 +0800

Sorry for this newbie question, but I'm really interested:

Can some tell me what a PIC is, and what it does, and what the

differences

between the PIC17 and 18?

Thanks...

Ted


At 08:48 PM 10/30/01 -0500, you wrote:

Must agree, 18 is way better than 17. Hopefully soon they'll

get all

their parts out in flash versions. Have you thought about

using the

dsPIC, when it comes out, to something ? I'm very excited

about that

part. Price wise, its very close to the PIC18-family. However,

its 16

bit and much faster.

From what I have read about the dsPIC it sounds impressive.

However at

present time I think I will have little use for it at work.

But I might

play around with it at home some when it come out, just for fun.
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Steve,

After working in the RF realm for many years, I had begun to wonder about
this same question...

Since you didn't quote or paraphrase I have no idea what question you've been
wondering about.

Jim

angtengchat,

Yeah, and it's ALL physics, so let's just have one group, physics, and we'll discuss everything there.

-Mike

From: "angtengchat" <angtengchat@...>

Yeah, solar...wind...geothermal. But what does this have to do with
electronics?

I suggest an alternative energy group/website.

generators is electronics, solar panels is electronics, windmills is
electronics ...... just in case you may not know.

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Mike,

Yes, microcontrollers are electronic devices, but the discussion of them has
generated so much traffic that they have their own group.

Should we discuss electronics on the Physics group?

Well, list groups are not necessarily so specialized that they don't overlap
topics. I would say that the group owner should decide but I see nothing
off topic about micro controllers. Unless you consider the list name,
Electronics 101. OTOH we were getting into some pretty abstract
and more advanced discussions of capacitors and charge.

Jim

hiya..

After working in the RF realm for many years, I had begun to wonder about
this same question... after looking around on the WWW for a while seeking
an answer, I came across a document which explained a little about this
issue... I can't say that this is the final answer, I'm not even sure
it's the actual truth of the matter, it's just what my research turned up,
and I'd certainly like to hear if any radio 'old-timers' know anything
about the true history of coax...

to the best of my recollection -

in the 'early' days of radio engineering, transmission lines were
constructed from those materials already "at-hand"... coaxial lines were
built using existing pipe and tubing sizes, with air as the dielectric, and
the inner conductor supported by bakelite discs at regular intervals.
(wonder how they made 'bends' in the line, used a junction box of some
sort?)

the "characteristic impedance" of any coax line is a function of the outer
diameter of the inner conductor, the inner diameter of the outer conductor,
and the dielectric material between them; be it air, teflon, or goat milk
cheese (probably not a good choice for low-loss cables).

as it happened, due to the sizes of the materials originally used, the
impedance fell right at about 50 ohms, and it sort of stuck as a standard.
later research is said to have revealed that lower impedance designs
produced transmission lines with greater bandwidth, while higher impedance
designs made for lower losses (less unit capacitance per unit length?)...

the choice of 75 ohms over 50 for systems such as cable television and
video (yes, Virginia, there *are* 75 ohm BNC connectors) was supposedly due
to these issues, a choice of less loss over greater bandwidth. seems kind
of odd, tho, I'd have guessed greater bandwidth to be more important than
loss for a multi-channel distribution arrangement.

the same article also claimed that the 'european' standard was 60 ohms.
I've never heard of that before, and from what I recall of working with
european equipment, it was always on a 50 ohm standard. the article was
also apparently written by an English fellow who may be having a bit of a
laugh over it all. anyone ever seen a Rohde & Schwartz RF signal generator
with a 60 ohm output? I haven't.

my best guess is that the idea regarding available materials is close to
the real story. the rest of the information... well, I'd like to do more
research before accepting it as gospel.

I'll welcome any comments, dissention, clarification, love/hate mail or
lunatic ramblings on the subject.


Steve H.

It doesn't sound like censorship to me. It's only censorship if the forum is a viable place to discuss that topic.

This isn't an open roundtable. What's the point of this being an electronics forum if people are talking about things that are NOT electronics?

Would it be censorship for a professor to refuse to talk about French in a Physics class?

-Mike

From: "Jonathan Luthje" <jluthje@...>
Reply-To: Electronics_101@...
To: <Electronics_101@...>
Subject: [Electronics_101] Not amused (was - Bomb)
Date: Fri, 2 Nov 2001 11:29:31 +1000

I am the owner of this list.
This subject is OFF TOPIC.
This topic is closed.

I hope that this will end the discusion and I will not have to take
further action.

Does this sound like "censorship" to anyone else but me? A blatent attempt
to force a topic off the list without so much as a peep.

I think that we are all big people who have more sense than to discuss a
topic such as this in depth without having to be *forced* to taboo it
because of the "list nazi". However giving a definition is not too much to
ask for - several of us have already stated that we will not answer the
question because it is "off topic".

Oh ... and BTW - an EFI system as used in automotive electronics is a type
of detonation controller as well ... can't discuss that either, I take it?

So in short - you won't have to "take furthur action" - because I'm
unsubscribing - to find a group that allows it's members to make it's own
decisions.


Cordial Regards,


Jon


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Yes, microcontrollers are electronic devices, but the discussion of them has generated so much traffic that they have their own group.

Should we discuss electronics on the Physics group?

-Mike

From: Mounir Shita <mshita@...>
Reply-To: Electronics_101@...
To: "'Electronics_101@...'" <Electronics_101@...>
Subject: RE: [Electronics_101] Re: PIC resources
Date: Thu, 1 Nov 2001 17:26:16 -0500

I would disagree with everyone who thinks PIC discussions doesn't belong to
this group either. I think we're beyond the times where you could do
everything with discrete components. These days microcontrollers belong as
much to Basic Electronics as a transistor and a diode.

Mounir

-----Original Message-----
From: d nixon [mailto:dnixon9@...]
Sent: Thursday, November 01, 2001 2:23 PM
To: Electronics_101@...
Subject: Re: [Electronics_101] Re: PIC resources


You'd get a better answer on the PIC group.

From: "Teodoro M. Villamarzo" <tedmv@...>
Reply-To: Electronics_101@...
To: Electronics_101@...
Subject: Re: [Electronics_101] Re: PIC resources
Date: Thu, 01 Nov 2001 12:28:19 +0800

Sorry for this newbie question, but I'm really interested:

Can some tell me what a PIC is, and what it does, and what the

differences

between the PIC17 and 18?

Thanks...

Ted


At 08:48 PM 10/30/01 -0500, you wrote:

Must agree, 18 is way better than 17. Hopefully soon they'll get all
their parts out in flash versions. Have you thought about using the
dsPIC, when it comes out, to something ? I'm very excited about that
part. Price wise, its very close to the PIC18-family. However, its 16
bit and much faster.

From what I have read about the dsPIC it sounds impressive. However at
present time I think I will have little use for it at work. But I might
play around with it at home some when it come out, just for fun.
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You have an FPGA in the design. What is the FPGA doing that it
cannot communicate with a lowly parallel port?

--- In Electronics_101@y..., adityanewalkar@y... wrote:

Hi,

--- In Electronics_101@y..., "manifold" <manifold_1@y...> wrote:

Are you considering designing an ASIC to communicate with the
parallel port of a PC?

Yes. We r communicating with Parallel Port of PC.

BTW somebody was asking for more information about this. So here
goes:

There is FPGA on the board which will be interfaced to PC by

parallel

port. This requirement of Parallel Port interface cannot change.

Now

we r configuring this FPGA means that there is about 2 MEGABITS of
data to be transferred really fast. We r using EPP mode for the
transfer. The FPGA will be configured and give the output back to
parallel port. Now will I require an ASIC to control the
communication between FPGA and Parallel Port??

regds,
Aditya.

How's this:

Interrupt Enable Bit
The parallel port interrupt was intended to allow interrupt-driven
transmission of data to a printer, but is not used by DOS and BIOS.
Versions of OS/2 prior to Warp (3.0) required the interrupt for
printing, but from Warp onwards the interrupt is not required (though
it can be used if the /IRQ switch is provided on the line in
CONFIG.SYS, e.g. BASEDEV=PRINT0x.SYS /IRQ).
The interrupt control bit controls a tri-state buffer that drives the
IRQ (interrupt request) line. Setting the bit to 1 enables the
buffer, and an IRQ will be triggered on each rising edge (low to high
transition) of the -ACK signal on pin 10 of the 25-pin connector.
Disabling the buffer allows other devices to use the IRQ line.
Important note: some older parallel ports trigger the interrupt on
the falling edge of -ACK.


--- In Electronics_101@y..., adityanewalkar@y... wrote:

Hi,
In EPP mode if the peripheral wants to communicate something

to the

PC, is there a way to interrupt the PC??

Though there is an interrupt bit defined in the standards,

Control

Port bit number 4 called Enable Interrupt Request; I am not finding
any resources on the perticular thing. Can somebody tell me sources
describing SPECIFICALLY ABOUT PARLLEL PORT INTERRUPT??

Please don't give me some sites giving BASIC information. I

want

specifically PARALLEL PORT INTERRUPT.

Thanx in advance.

Aditya N.

Yes there is an easier way. There is a simulation package from
Linear Technology. It is a free spice simulator tailored for fast
simulation of switching power supplies. You can add one of their
parts or an assortment of comparators, op-amps or other general parts.

The Linear Tech simulation package is not as easy to use for general
purpose spice as the free version of Micro-cap but ir works very well
for switching power supply circuits. The Micro-cap product will also
model switchng supply circuits but not as fast. For the comparator
circuit you are building either one should work well.

How well do simulations model the real world of switching power
supplies? Pretty well. The results may not be exacly the same, the
frequency may be off the diode may drop a little more voltage etc.
but what you get to do in the simulation is change the part values
and see what happens. Find out what is sensitive and what really
does not work before you build it. In the end you will still need to
make adjustment to the design.






--- In Electronics_101@y..., gt bradley <gt6@l...> wrote:

For various reasons, I have decided to build a "simple" buck

regulator

aka ripple regulator.

I believe I can come up with decent choices for the comparator, the

FET

and various resistors, This leaves choosing values for the Cap and

the

inductor.

It seems that since my references have calculations that

are "tuned" to

power supplies frequency, (which makes a lot more sense on a PWM

P/S)

Since changing the values, will change the frequency, I'm guessing

at

the process.

Is it reasonable to derive a frequency calculating the oscillation

with

no filtering (just the delays in switching), and then add

components for

those values, (even though they will slow the oscillation down?).

or would I calculate one component, then the other, then

recalculate the

first, going back and forth until the change in value is less than

some

epsilon?

Is their an easier way?

I'll play with the numbers this week-end.
GT

Hi guys, Curtis here.

I've been watching this "bomb" thing go around (and
around ... and around)

I've gotta say something .....

I know everyone will turn around ... and ask "OK
Curtis... so whose side are YOU on??".

To me, it's not a question of sides! I've heard "Jim"
.. and he's got his good points.

I've also heard "Angtenchat" (forgive me if I spelled
it wrong) .... and believe it or not ... I think he's
making a good point of "censorship" as well.

BOTH of them HAVE GOOD POINTS!!!

The problem is ... this is NOT the place to carry on a
debate like this.

Maybe an example would help. It's like two guys
fighting over a girl. Each loves the girl very much
and (in their own minds) is defending that love VERY
HONORABLY. So they're swinging punches ... kicking
... and so on.

But little do they realize (being in the heat of a
battle) that this fight has (slowly) moved onto a
Kindergarten school Playground.

So they're kicking (and punching). And all these
little kindergarten munchkins .... stare ... and
watch.

Then one of the kids asks their teacher and says
"excuse me Mr. teacher ... is THIS a good example of
PROPER ADULT BEHAVIOR???".

And then the teacher is STUCK ... as to what to say!!

This is Peter's (the owner of this list) house. We're
guests of his house. Right now, Peter has to answer
questions from other guests as to "the kinds of people
Pete hangs around with" On this list, that is.

And frankly, I wouldn't blame him for being quite
embarrased!

So please guys (Ang and Jim) ... look around. At all
the guests staring. And say to each other civil-ly,
"We'll take this debate outside"

Then both of you join another group. Like a "How
America is turning into a tyranical government" group
... or something like that.

Then BOTH of you end up as winners. Cause I'll say it
AGAIN. BOTH of you make a PRETTY GOOD POINT!!!!!

That's my take on it anyways ....

Curtis


--- Jim Purcell <jpurcell@...> wrote:

angtengchat,

unsubscribing - to find a group that allows it's

members to make it's own

decisions.

<snip>

You make it sound like tyranny, when all it is is
bringing
order out of potential chaos.

Jim

=====
*
* *
* Your website deserves a taste of rush hour traffic *
* *
* *
*

__________________________________________________
Do You Yahoo!?
Find a job, post your resume.

Rachel,
This is correct. A DC current flows through the entire conductor. As the frequency rises, the current moves out of the center of the conductor towards the surface. This is called "the skin effect". Lightning consists of multiple fast pulses, i.e. it is high frequency and therefore flows on the surface.
There is a professional golfer that has been struck and survived. Look up Lee Trevino on the web, the article on him says that stikes are fatal about %30 of the time.

Doug

Rachel wrote:

Gil,
Go look at the "Analog Devices" (www.analog.com). They have some very interesting stuff - but they also have some analog switches designed specifically for what wou are doing., specifically the SSM2402, SSM2404, and the SSM2412

Go to www.analog.com. Click on "Products and Datasheets". Click on " Master Product Index". Scroll to the bottom.

Doug Hale




Gil wrote:

Here's my question: I need to make really what amounts to no more
than a 6-Pole 2-Throw switch for line-level audio signals. Although

I

could do this mechanically, I was wondering how you would address
this problem electronically?

Hi!
It all depends on the electrical characteristics of the signals you
wish to switch. A transistor solution is simple and cost effective
for higher currents. If you need a switch for small signals, you have
a few CMOS and TTL IC?s made for this function. most of them use the
same command signal, so you can?t control the switches individually.
The HC4016 are quad bilateral CMOS switches. 4066 is alike. once they
can be used to drive transistors I think they are a good solution. On
the other side if you need to switch RF these will not work very well
because of parasitic capacitances...
c u

Hi,
Another beginner here.

Here's my question: I need to make really what amounts to no more
than a 6-Pole 2-Throw switch for line-level audio signals. Although I
could do this mechanically, I was wondering how you would address
this problem electronically?

Thanks.

--- In Electronics_101@y..., Curtis Sakima <electronichobbyist@y...>
wrote:
[snip]

Yeah, I think the 3914 (in my opinion anyways) would
probably be your best bet. However, it's not "because
you want to measure voltage". It's 'cause of the
CALIBRATION.

Ok, I'm going to try the LM3914, and draw up a schematic. I'll be
back for critique when I get it drawn up. :)

Thanks,
Brian

angtengchat,

unsubscribing - to find a group that allows it's members to make it's own
decisions.

Please let me know if you found one, I would like to join you too.

Which is more important to you, to be able to discuss a common
topic, in this case electronics, or to just talk about anything
you want any old time. It's not that doing so is a bad idea
but most of the people in groups and lists I have been in
prefer that the topic be adhered to for the most part.
You make it sound like tyranny, when all it is is bringing
order out of potential chaos.

Jim